Improved furnace for smelting of lead



DRUMMOND & FULLER.

Smelting Lead Ore.

Patented May 30. I838.

flaw 76211 06 W UNITED STATES PATENT OF IC ROBERT A. DRUMMOND AND G. W. FULLER, OF GALENA, ILLINOIS.

IMPROVED FURNACE FOR SMELTING OF LEAD.

Specification forming part of Letters Patent No. 757, dated May 30, 1838; antcdated I November'BO, 1837.

T0 60% whom it mag concern:

Be it known that we, R0121. A. DRUM- MOND and GEQW. FULLER, of Galena, J 0 Da spread on the hearth, to very near an equalitywith the open space in the flue or flues, in order to give velocity to the current (which accelerated motion of the agents of separation compensates for the diminution of spaces) of flame and heated air while passing over the ore; and also in so constructing the hearth.

that it may be kept partially cool, so that the zain or unmelted portions of the ore (which always run from the mineral when smelting) may run down into the cooler part of the hearth, where it assumes a solid state, while the lead, that retains its liquidity at a much lower temperature, runs off.

To enable others to construct and use our invention,we give the following description of the mode of building and operation.

WVe build of materials similar to those of the English reverberatory or air furnace, but the proportions are very dissimilar. For example, the English air-furnace of common size is of dimensions nearly as follows: the firebridge, fifteen or eighteen inches in height above the hearth; the opening from the firehouse over fire-bridge to arch, one foot by four in width; the length of furnace inside, ten feet; breadth at fire-bridge, eight, tapered down to about sixat fines, space from hearth to arch varying from eighteen inches to thirty; two flues, about ten or twelve inches in diameter, leading off to a stack thirty-five or forty feet in height; three openings on. each side for working the ore when in the furnace. Now, the dimensions of our improved air-furnace to do a business equal to the above: the firebridge from hearth AA up, four to six inches in height; the opening 13, from firebridge to arch, four inches by four feet six inches wide;

length of furnace inside, six feet;-breadth at fire-bridge, four feet six inches, tapered down to about three feet eight inches at fines, space from hearth to arch varying from six to eight inches; two flues, a 0, about the same in diameter as the English air-furnace, continued directly up, or after the fashion of the English; or, that not being a material part, it may be varied in a height or position to suit the notion of the builder. of a furnace upon our plan need never be increased beyond one, D, on each side, as the furnace is so much diminished in length that we can command the whole of the inside by a door or opening, 0, at the end. The construction of the bottom or hearth ct a by us is managed in various ways. The preferable one, however, that we have used is to lay bricks on their edges a few inches apart, 'so as to admit a free circulation of cold air (from without) between them by means of a few small opening through the walls, and laying on top of these brick sheet-iron, and then run slag three or four inches thick, which forms a very permanent hearth.

The mode of operating on these furnaces is very similar to that on the English plan, except that the use of coal and lime mixed withthe ore or with the slag used for the reduction of oxidized lead is entirely dispensed with and use less with ours. The firehouse of our furnace is very much like the English, except dimi nution of about a fourth in all its inner dimensions.

Vhat we claim as our invention, and desire to secure by Letters Patent, is-

1. Not the mere reduction in the general dimensions of our furnace when compared with what is known as the English furnace; but to such a mode of construction and of proportioning the respective parts, as above described, as promotes the separation of the lead from its mineralizer with greater facility and economy than has been heretofore attained- 'a result which is principally dependent upon the acceleration of the current of heated air in contact with the ore in our furnace.

2. The manner of constructing the hearth of the furnace, as above described, by which we The openings in the sides a are enabled to keep it at a comparatively low i1ya1esult not obtained in the English furtemperature, which not only renders it very nace.

desirable, but prevents the formation of slag, ROBT. A. DRUMMOND. and causes also the minor unseparated par- G. \V. FULLER.

ticles of ore to become chilled, preventing the \Vitnesses:

running thereof down, While the reduced lead, R. S. NORRIS,

being in a perfectly fluid state, escapes read- I ELI-TAI-I CHARLES. 

